The sentence confuses me. Is 'Moony' the nickname of his friends or his? I interpret it as: "his friends gave him the nickname Moony" or "He was addressed with the nickname Moony among his friends". What's the correct way to understand it?

1 Answer
1

Three things make it clear that "Moony" was the nickname of the author / first person:

He begins by saying "I'm Moony" so he is talking about his nickname.

It says it was his friends' nickname for him. If it was the nickname by which the writer's friend was called, it would simply say "it was my friend's nickname".

It says "my friends' nickname for me", not "my friend's nickname for me. The placement of the apostrophe indicates that many friends called him by this nickname, not just one. All of his friends cannot have the same nickname.

It is worth noting that the true definition of a "nickname" is a name given to a person by others. Some internet applications use the term "nickname" for a pseudonym that you choose yourself and as such the meaning may have shifted slightly in modern use. However, some nicknames given to others are pejorative - not something one would choose to be called.